Catheter loop manager

ABSTRACT

A catheter loop manager apparatus which controls the slack portion of a catheter located adjacent to an implanted pump and prevents fibrotic encapsulation of the slack catheter portion. The catheter loop manager comprises a retainer element configured to associate with an implantable pump and to releasibly hold or retain a loop or section of catheter adjacent to the pump. A pull tool is used to releasibly engage a catheter section and pull the catheter section into a loop within a retention channel in retainer element.

FIELD OF THE INVENTION

This invention pertains generally to implantable drug delivery systems,and more particularly to a catheter loop manager which controls theexcess catheter at the pump end to prevent fibrotic encapsulation of thecatheter slack and avoid damage to the catheter during pump replacementprocedures.

BACKGROUND OF THE INVENTION

Implantable drug delivery devices are increasingly used as therapeutictools for treatment of a variety of conditions and diseases, especiallywhere a prolonged period of therapy is required. Implantable drugdelivery devices avoid patient inconvenience and discomfort associatedwith administration of multiple doses of an agent, and further providefor enhanced therapeutic benefits due to avoidance of bolus doses,improved patient compliance with dosage regimens, and providinggenerally a constant blood serum level of delivered drugs.

Various implantable drug delivery systems have been developed usingdifferent technologies to accomplish movement of drug (typically in adrug formulation, e.g., a solvent) from within a reservoir in the devicethrough an exit port or orifice to a treatment site in the subject.These delivery technologies have been based on, inter alia, diffusive,erodible, and convective mechanisms. Exemplary delivery systemsemploying convection include, but are not limited to, electromechanicalpumps, osmotic pumps, electro-osmotic pumps, electro-chemical pumps,hydrolytic systems, piezoelectric pumps, elastomeric pumps, vaporpressure pumps, and electrolytic pumps.

The location of a specific drug delivery site in the body often will benon-optimal for locating an implantable pump. This situation occurs, forexample, in the delivery of hydromorphone to the spinal column. In suchinstances the pump is implanted remotely from the actual drug deliverysite and the is drug transported from the pump to the delivery site viaan implanted catheter. Generally, an excess length of catheter tubing isrequired adjacent the pump implant incision to provide sufficient slackto allow external assembly of the pump and catheter end prior toimplanting. When the pump is inserted into the implant incision, theexcess portion of catheter will form a slack loop adjacent to the pump.

The presence of an uncontrolled, slack, excess portion of catheterwithin the implant incision creates some important problems. Theuncontrolled portion of catheter may kink or otherwise adopt aconfiguration which hinders drug delivery after the implant incision isclosed and sutured. The slack portion of catheter will ultimately becomefibrotically encapsulated in the tissue adjacent to the pump. Theinternal drug reservoir of the implanted pump will become depleted overtime and require replacement, and the fibrotically encapsulated cathetergreatly complicates pump replacement. Since the location of the slackportion of catheter is not predictable, the catheter may beinadvertently cut or otherwise damaged by a scalpel during an incisionto replace the pump. The fibrotic encapsulation of the slack portion ofcatheter makes it difficult to remove the pump from the incision withoutdamaging the catheter at the pump connection, and careful surgicalexcision is often necessary to free the spent pump. Damage to thecatheter end will typically require re-implantation of the entirecatheter at substantial cost, inconvenience and patient discomfort.

There is accordingly a need for a catheter loop manager which controlsthe excess or slack portion of catheter associated with an implantedpump, which holds the slack portion in a precisely controlled loopadjacent to the pump, which avoids fibrotic encapsulation of slackcatheter portions, and which generally avoids surgical complicationsassociated with have heretofore interfered with replacement ofimplantable pumps. The present invention satisfies these needs, as wellas others, and generally overcomes the deficiencies found in thebackground art.

SUMMARY OF THE INVENTION

The present invention is a catheter loop manager apparatus whichcontrols the slack portion of a catheter located adjacent to animplanted pump and prevents fibrotic encapsulation of the slack catheterportion. In general terms, the catheter loop manager comprises aretainer element configured to associate with an implantable pump and toreleasibly hold or retain a loop or section of catheter adjacent to thepump. More preferably, the retainer element couples to the implantablepump and retains a loop of catheter in close proximity to the pump at aknown location, preferably within a channel in the retainer element. Thecatheter loop manager also preferably comprises a pull tool configuredto releasibly engage a catheter section and pull the catheter sectioninto a loop within the retainer element.

By way of example, and not necessarily of limitation, the retainerelement includes an elongated, tubular retainer body with an externalsurface structured and configured to conform to the outer surface of animplantable pump. A tip portion is joined to the first or front end ofthe retainer body and includes a bore configured to receive a connectorferrule on the pump. The bore in the tip portion allows a catheter endto couple to the ferrule while the retainer element is mounted on theimplantable pump. The retainer body and tip portion are preferablyintegral to each other, with the retainer element being fabricated froma single piece of resilient, elastomeric polymeric material such as asilicone rubber. One or more lateral grooves may be included on theexterior surface of the tip portion and/or retainer body to accommodatesutures and facilitate the suturing of the loop manager and pump withinan implant incision.

An elongated channel extends through the retainer body and communicateswith the front and back ends thereof. When the retainer element isjoined to the pump, the channel is substantially aligned with thelongitudinal axis of the pump. The elongated channel in the retainerbody and the bore in the tip portion preferably are substantiallyparallel in orientation with respect to each other. The channel isstructured and configured to slidably receive the pull tool and toretain an elongated loop of catheter therewithin. The pull tool includesa hook adjacent a first end which is configured to fit through theelongated channel and releasibly engage a catheter. The pull tool alsopreferably includes a handle portion at a second end to facilitatemanipulation.

During pump implant procedures, a slack or excess “service” portion ofcatheter is generally provided adjacent the pump implant incision toallow manipulation of the pump while it is attached to the catheter. Thecatheter loop manager of the invention advantageously provides controlof the slack portion of catheter and avoids damage thereto by holdingthe excess catheter portion as a catheter loop within the channel of theretainer body.

In operation, the retainer element is coupled to a pump prior toimplanting. The catheter end is passed through the bore in the tipportion and affixed to the connector ferrule. The connector ferrule onthe end of the pump fits into the bore in the tip section, and thearcuate surface on the retainer body is positioned adjacent to thecylindrical body of the pump. The hook of the guide tool is then passedthrough the channel in the retainer body and is used to hook orotherwise engage the slack portion of the catheter and draw the catheterportion into the channel of the retainer body. As the slack portion ofcatheter is drawn into the retainer body it forms a well defined loopwithin the channel which will provide a “service loop” for subsequentpump replacement procedures. The hook on the pull tool is thendisengaged, and the pump and attached retainer element with the internalcatheter loop are positioned within the pump incision and sutured intoplace using the lateral grooves on the retainer element, after which theincision is closed. The catheter loop is retained within the channel forthe duration of the implant.

When the drug reservoir internal to the implanted pump has becomedepleted, a new incision is made to remove the depleted pump. Since theslack portion of catheter is retained or “managed” within the retainerelement, there is no risk of cutting the catheter portion. The suturesholding the pump and retainer element in place are removed, and the pumpand attached retainer element are withdrawn from the incision. The loopof catheter is withdrawn from the channel in the retainer body as thepump and retainer element are removed from the incision to again providea service portion of catheter to facilitate handling of the pump priorto detachment of the catheter, and the attachment of a new pump. Sincethe excess catheter portion has been retained within the channel of theretainer body for the duration of the implant, the excess catheterportion is free from any fibrotic inclusion by surrounding tissue whichwould otherwise have occurred. The retainer element and exhausted pumpmay be disposed of, or the retainer element may be detached from thespent pump, sterilized, and re-used.

The invention thus provides a method for managing a service loop orportion of catheter associated with an implant incision which comprisesproviding a retainer element in association with an implantable pump,affixing a catheter end to a connector on the pump, and drawing anexcess portion of catheter into the retainer element to form a catheterloop therein. The method also preferably comprises withdrawing thecatheter loop from the retainer element, after depletion of the pump, toform a service portion of catheter. The method further preferablycomprises coupling the retainer element to the pump, and suturing theretainer element and pump within the implant incision.

An object of the invention is to provide a catheter loop manager whichretains a service portion of catheter as a loop within a retainerelement associated with an implanted pump.

Another object of the invention is to provide a catheter loop managerwhich prevents the service portion of a catheter from becomingfibrotically enclosed within tissue during the implant period of animplantable pump.

Another object of the invention is to provide a catheter loop managerwhich prevents inadvertent damage to the service portion of a catheterduring implantable pump replacement procedures.

Another object of the invention is to provide a catheter loop managerthat avoids kinking or restriction of a catheter associated with animplanted pump which would interfere with drug delivery from the pumpthrough the catheter.

Another object of the invention is to provide a catheter loop managerwhich facilitates the surgical procedures associated with implanting andinterchanging of implantable pumps.

Further objects and advantages of the invention will be brought out inthe following portions of the specification, wherein the detaileddescription is for the purpose of fully disclosing the preferredembodiment of the invention without placing limitations thereon.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The present invention will be more fully understood by reference to thefollowing drawings, which are for illustrative purposes only.

FIG. 1 is a perspective view of a catheter loop manager apparatus inaccordance with the present invention shown together with an implantablepump and a section of catheter.

FIG. 2 is an exploded view of the catheter loop manager apparatus andassembled implantable pump and catheter of FIG. 1.

FIG. 3A through FIG. 3D illustrate the use of the catheter loop managerapparatus of the invention, with the retainer element shown incross-section.

DETAILED DESCRIPTION OF THE INVENTION

Referring more specifically to the drawings, for illustrative purposesthe present invention is embodied in the apparatus and method showngenerally in FIG. 1 through FIG. 3. It will be appreciated that theapparatus may vary as to configuration and as to details of the parts,and that the method may vary as to details and the order of the steps,without departing from the basic concepts as disclosed herein. Theinvention is disclosed generally in terms of use with an implantablepump for drug delivery applications. However, it will be readilyapparent to those skilled in the art that the invention may be used tocontrol the end portion of an implanted catheter in various situationswhere management of the catheter end is desirable, and the details andspecificities discloses herein are only exemplary and should not beconsidered limiting.

Referring now to FIG. 1 through FIG. 3, a catheter loop managerapparatus 10 in accordance with the present invention is shown togetherwith an implantable pump 12 and a section or portion of catheter 14having an end 16. The catheter loop manager apparatus 10 comprises aretainer element 18 configured to couple to or otherwise associate withimplantable pump 12, and a pull tool 20 used with retainer element 18 asdescribed in more detail below. Implantable pump 12 may be any type ofpump including, for example, mechanical, electrical, osmotic, diffusion,electrochemical etc. The catheter loop manager 10 of the invention may,however, be used with any type of implantable pump.

Retainer element 18 preferably includes an elongated, tubular retainerbody 22 with first and second ends 24, 26. A longitudinal channel 28extends through retainer body 22 and communicates with ends 24, 26.Retainer body 18 preferably has an elongated arcuate surface 29 which isstructured and configured to conform to the outer surface of implantablepump 12, with retainer body 22 and channel 28 being oriented in adirection substantially parallel to the longitudinal axis (not shown) ofpump 12 when retainer element 18 is coupled to pump 12.

Retainer element 18 also preferably includes a tip portion 30 joined tofirst end 24 of retainer body 22. Tip portion 30 includes a bore 32extending therethrough which is structured and configured to accommodatea connector ferrule 34 on pump 12. Bore 32 is also structured andconfigured to allow catheter end 16 to pass through bore 32 and join toconnector 34. Tip portion as shown is tapered or cone-shaped, andincludes a generally flat back surface 36 which conforms in shape to thetop end 38 of pump 12. The channel 28 in retainer body 22 and bore 32 intip section preferably are substantially parallel to each other inorientation.

Retainer body 22 and tip portion 30 preferably are integral to eachother, with retainer element 18 being fabricated from a single moldedpiece of resilient or flexible polymeric material such as siliconerubber or like material. Preferably, one or more grooves 40 extendlaterally around tip portion 30 and communicate with corresponding holes42 which extend laterally through retainer body 22. Grooves 40 and holes42 accommodate sutures (not shown) that hold retainer element 18 andpump 12 in place within an implant incision as described further below.

Pull tool 20 preferably comprises an elongated resilient section 44having a hook 46 adjacent a first end 48 and a handle 50 adjacent asecond end 52. Hook 46 and elongated section 44 are preferablyfabricated from resilient metal wire, and are structured and configuredto slidably fit through the elongated bore 28 in retainer body 22. Hook46 is structured and configured to releasibly engage or hold cathetersection 14.

Catheter section 14 as shown in FIG. 1 and FIG. 2 is generally the endportion of an elongated flexible catheter (not shown) that is implantedwithin patient, with catheter section 14 being the portion of catheterwhich extends out of an implant incision (not shown) in the patient.Catheter section 14 comprises a slack or “service” portion of catheterwhich allows handling of pump 12 by a surgeon after connector 34 on pump12 has been coupled to the end 16 of catheter section.

FIG. 3A through FIG. 3D illustrate generally the method of theinvention. Prior to the implanting of pump 12, the retainer element 18is coupled to pump 12. Catheter end 16 is passed through bore 32 in tipportion 30 and coupled or affixed to connector ferrule 24. Tip portion30 is fitted over connector ferrule 34 on pump 12, with connectorferrule tensionally engaging the interior of bore 32 to hold retainerelement 18 onto pump 12, with flat surface 36 or up portion 30 adjacentto the top end 38 (FIG. 2) of pump 12, and with arcuate surface 29 onretainer body 22 positioned adjacent the cylindrical exterior of pump12. A biocompatible adhesive may be used to further secure retainerelement 18 to pump 12. The slack or excess catheter portion 14 allowspump 12 and the attached retainer element 18 to be manipulated by asurgeon during the implant procedure.

Hook 46 and elongated section 44 of pull tool 20 are inserted intochannel 28 in retainer body 22 at second end 26 and are passed throughthe elongated channel 28 as shown in FIG. 3B so that hook 46 extends outof channel 28 at first end 24. Catheter section 14 is then engaged byhook 46, and hook 46, together with the engaged catheter section 14, aredrawn back into channel 28 in retainer body 22 as shown in FIG. 3C, withcatheter section 14 forming a loop 54 as it is pulled through channel 28by hook 46. Once loop 54 has been drawn or pulled through channel 28 tosecond end 26, hook 46 is disengaged from catheter section 14 to leavethe looped catheter section 14 within channel 28. At this point the pump12 and attached retainer element 18 may be sutured in place at a desiredlocation within the implant incision utilizing suture grooves 40 andholes 42 (sutures are not shown), after which the implant incision isclosed. The looped catheter section 14 is retained within channel 28 inretainer element 14 adjacent to pump 12 for the duration ofimplantation. The looped catheter section 14 thus is protected fromunwanted fibrotic encapsulation by tissue surrounding the implantedpump, which would otherwise occur if catheter section 14 were left freeor unmanaged within the implant incision.

The drug reservoir (not shown) internal to pump 12 will ultimatelybecome exhausted or depleted during the implant period, typically afterseveral weeks or months, and pump 12 will require replacement. A newincision (not shown) then is made to remove the depleted pump 12. Sincethe excess catheter portion 14 is retained or “managed” within theretainer element 18, there is no risk of cutting the catheter portion 14with a scalpel when the new incision is made. The sutures holding thepump 12 and retainer element 18 in place are removed, and pump 12 andthe attached retainer element 18 are withdrawn from the incision. Aspump 12 and retainer element 18 are withdrawn, the looped cathetersection 14 is withdrawn from channel 28 in retainer body 22 as shown inFIG. 3D to again provide a service portion of catheter to facilitatehandling of pump 12 by a surgeon. The retention of the catheter section14 within retainer element 18 during the implant avoids fibroticencapsulation of catheter section 14 as noted above, and cathetersection 14 is thus immediately available as a service loop withoutrequiring any additional procedure to remove catheter section 14 fromsurrounding tissue. Catheter end 16 is detached from connector ferrule34 to allow attachment to a replacement pump, which is then implanted bygenerally repeating the above procedure. The same retainer element 18may be used with the replacement pump, or the retainer element 18 may bedisposed with the spent pump.

Accordingly, it will be seen that this invention provides a catheterloop manage apparatus and method which controls the slack portion of acatheter located adjacent to an implanted pump and prevents fibroticencapsulation of the slack catheter portion which could otherwise leadto damage to the catheter portion or complication of the implantprocedure. Although the description above contains many specificities,these should not be construed as limiting the scope of the invention butas merely providing an illustration of the presently preferredembodiment of the invention. Thus the scope of this invention should bedetermined by the appended claims and their legal equivalents.

1. A catheter loop manager comprising a retainer element configured toassociate with an implantable pump and to releasibly hold a loop ofcatheter.
 2. The catheter loop manager of claim 1, wherein said retainerelement is configured to coupled to said implantable pump and to holdsaid loop of said catheter adjacent to said implantable pump.
 3. Thecatheter loop manager of claim 1, wherein said retainer elementcomprises a retainer body and a tip portion coupled to a front endthereof, said tip portion configured to engage a catheter connector onsaid implantable pump, said retainer body configured to hold said loopof said catheter.
 4. The catheter loop manager of claim 3, wherein saidretainer body includes an internal channel, said channel configured tohold said loop of said catheter therein.
 5. The catheter loop manager ofclaim 4, further comprising a pull tool, said pull tool having a hookconfigured to fit through said channel and releasibly engage saidcatheter.
 6. A catheter loop manager apparatus comprising a retainerelement configured to couple to an implantable pump and releasibly holda loop of catheter adjacent to said implantable pump.
 7. The catheterloop manager apparatus of claim 6, wherein said retainer elementincludes an elongated retainer body having an elongated channelextending therethrough, said channel configured to hold said loop ofcatheter.
 8. The catheter loop manager apparatus of claim 7, whereinsaid retainer element further comprises a tip portion joined to a firstend of said elongated retainer body, said tip portion configured toengage a catheter connector on said implantable pump.
 9. The catheterloop manager apparatus of claim 8, wherein said tip portion includes abore, said bore configured to fit over said catheter connector and allowan end of said catheter to couple to said connector.
 10. The catheterloop manager apparatus of claim 7, further comprising a pull tool, saidpull tool having a hook configured to pass through said channel andreleasibly engage said catheter.
 11. The catheter loop manager apparatusof claim 6, wherein said retainer element includes at least one lateralgroove configured to accommodate a suture.
 12. A catheter loop managerapparatus usable with an implantable pump, said catheter loop managerapparatus comprising: (a) a retainer element having an elongated channelextending therethrough said channel configured to retain a loop ofcatheter; and (b) a pull tool having a hook configured to fit throughsaid elongated channel and draw said loop of said catheter into saidchannel.
 13. The catheter loop manager apparatus of claim 12, whereinsaid retainer element is configured to coupled to said implantable pump.14. The catheter loop manager apparatus of claim 13, wherein saidretainer element comprises an elongated retainer body and a tip portionjoined to said elongated retainer body, said channel extending throughsaid elongated retainer body, said tip portion configured to fit over acatheter connector on said implantable pump.
 15. The catheter loopmanager apparatus of claim 14, wherein said elongated retainer bodyincludes an arcuate surface configured to conform to said implantablepump.
 16. The catheter loop manager apparatus of claim 13, wherein saidtip portion includes a bore configured to fit over said catheterconnector and allow a catheter end to affix to said catheter connector.17. The catheter loop manager apparatus of claim 12, wherein saidretainer element includes at least one lateral groove configured toaccommodate a suture.
 18. A method for managing a service loop ofcatheter in association with an implantable pump, comprising: (a)providing a retainer element, (b) affixing a catheter end to a connectoron said pump; and (c) drawing an excess portion of catheter into saidretainer element to form a catheter loop therein.
 19. The method ofclaim 18, further comprising coupling said retainer element to saidpump.
 20. The method of claim 18, further comprising couplingwithdrawing said catheter loop from said retainer element afterdepletion of said implantable pump.
 21. The method of claim 19, furthercomprising suturing said retainer element and said implantable pumpwithin an implant incision.
 22. The method of claim 18, wherein saidretainer element includes a channel extending therethrough and saiddrawing is carried out with a pull tool having a hook configured to passthrough said channel and engage said excess portion of catheter.